USING WASTE HEAT TO WARM HOMES
The idea is simple, take ‘waste heat’ from the factories, thermal energy plants, industrial cooling systems, abandoned mines, rivers and the London underground and then pipe it into near by homes.
The excess heat generated in different ways by these can be captured and distribute near by to keep buildings warm. The idea is gaining in popularity with councils across the UK as a way for them to drastically cut carbon emissions and provide heat across the area.
The amount of heat generated by the tube in London is well known by those that travel on it. The idea is that now the heat generated by the trains will soon be keeping people and businesses in Islington warm and cosy through the chillier months.
By the end of the year the project will pipe heat from the underground into the homes and businesses above. The idea is part of a growing number of schemes across the country to start using ‘waste heat’ from factories, power plants, rivers and disused mine shafts.
One reason for the step forward in these ideas is that the government has pledged to ban gas-fired boilers from new build houses from 2025. This has caused a flurry of activity to find new sources of renewable heat.
Islington already has schemes using waste energy to heat buildings. They channel heat from the Bunhill Energy Centre, which generates electricity, this heat is sent into council houses, schools and a leisure centre. They are due to expand this project to heat a further 450 homes in the near future.
The tube heating project could be spread across the capital with more boroughs following suite as they realise the benefits of using the cheap, low carbon heat from the underground lines. Another benefit that may come from this is a reduced temperature in the underground networks as the heat is removed.
There are estimates that the waste heat created by the underground is enough to meet 38% of the city’s heating demands. That is huge! The idea that 38% of London could be heated by energy coming from the tube, combining this idea with the other plans could lead to a majority of the city with clean, low carbon heating.
Tim Rotheray, director of the Association for Decentralised Energy believes these heating schemes are a way to help with the climate crisis. He also states ” Almost half the energy used in the UK is for heat, and a third of UK emissions are from heating. With government declaring that we must be carbon neutral within 30 years we need to find a way to take the carbon out of our heating system;”
These ideas are gaining in popularity across the country as councils realise the potential of these schemes to help them provide people with heat and a very effective tool to reduce carbon emissions and help them combat the climate crisis.
“The opportunity that has become clear to the decentralised energy community is the idea of capturing waste heat and putting it to use locally.”Tim Rotheray
In urban and industrial areas, waste heat is a by product of any cooling system, thermal power plant or heavy industry. The biggest factor and key to harvesting this heat is to distribute and use it locally.
A factory owned by British Sugar is Wissington, Norfolk, pipes the excess heat that it creates from cooking syrup into a neighbouring 18-hectare greenhouse used to grow medical cannabis. It also pumps some of its carbon emissions into the green house to create a carbon heavy environment for the plants to develop better and convert the C02 into oxygen.
Recently Stoke-On-Trent started work on a £52m project to use energy from hot water deposits deep underground. This will allow the water to be naturally heated before it is pumped through the existing network to customers.
The Stoke project is said to be ready by winter of 2020. The council estimates that the scheme will cut carbon emissions by an estimated 12,000 tonnes a year.
A source of energy which lies beneath many British towns and cities comes in the form of water which can hold and retain energy as it is trapped at the bottom of old mines. Engineers in Edinburgh have come up with a plan to create a heat network that uses water found in the enormous disused mines as a giant thermal battery.
They believe the mine water has “massive potential” to help the city achieve its sustainability goals by connecting it to a renewable heating and cooling distribution system.
The mine system beneath the city is at around 500 meters below ground and flooded. The system measures 8km in length by 6km wide.
During the summer months the heat produced by cooling systems and heavy industry could be pumped down into the water where it will gradually raise the temperature of the water. From this during the winter months the water would be pumped to the surface and the ‘low grade’ heat will be extracted in a heat exchanger. The water can then be taken and pumped through a heat pump for heating homes and businesses through out the city.
Engineers in Glasgow have even discovered a heat potential in the River Clyde. The city’s £250m Queen’s Quay regeneration project will use heat pumps to extract heat from the river water before piping it into a 2.5km long network that will pass through 1,400 homes, businesses and public buildings.
It is hoped that it will provide a warm welcome to the 30,000 delegates due to attend the UN climate talks in Glasgow next year.
The fight to reduce carbon emissions across the planet may seem insurmountable but as people bring new ideas to the table and these ideas are shared between us many solutions can be found. Working together and with a combination of programs, projects and ideas we will find a way to achieve what we need to in order to avoid the biggest threats posed by climate change. Reusing ‘waste heat’ is a one of them and will be added to the bigger picture.